package com.lagou.cl.factory;

import com.lagou.cl.annotation.MyAutowired;
import com.lagou.cl.annotation.MyComponet;
import com.lagou.cl.utils.TransactionManager;
import net.sf.cglib.proxy.Enhancer;
import net.sf.cglib.proxy.MethodInterceptor;
import net.sf.cglib.proxy.MethodProxy;

import java.lang.reflect.InvocationHandler;
import java.lang.reflect.Method;
import java.lang.reflect.Proxy;

/**
 * @author 程  林
 * @date 2020-04-01 10:20
 * @description //代理对象工厂：生成代理对象的
 * @since V1.0.0
 */
@MyComponet
public class ProxyFactory {


	@MyAutowired
	private TransactionManager transactionManager;

	/**
	 * Jdk动态代理
	 *
	 * @param obj 委托对象
	 * @return 代理对象
	 */
	public Object getJdkProxy(Object obj) {

		// 获取代理对象
		return Proxy.newProxyInstance(obj.getClass().getClassLoader(), obj.getClass().getInterfaces(),
				new InvocationHandler() {
					@Override
					public Object invoke(Object proxy, Method method, Object[] args) throws Throwable {
						return processPointCut(method, args, obj);
					}
				});

	}

	/**
	 * 使用cglib动态代理生成代理对象
	 *
	 * @param obj 委托对象
	 * @return
	 */
	public Object getCglibProxy(Object obj) {
		return Enhancer.create(obj.getClass(), new MethodInterceptor() {
			@Override
			public Object intercept(Object o, Method method, Object[] args, MethodProxy methodProxy) throws Throwable {
				return processPointCut(method, args, obj);
			}
		});
	}


	private Object processPointCut(Method method, Object[] args, Object obj) throws Throwable {
		Object result = null;

		try {
			// 开启事务(关闭事务的自动提交)
			transactionManager.beginTransaction();

			result = method.invoke(obj, args);

			// 提交事务

			transactionManager.commit();
		} catch (Exception e) {
			e.printStackTrace();
			// 回滚事务
			transactionManager.rollback();

			// 抛出异常便于上层servlet捕获
			throw e.getCause();
		}

		return result;
	}

}
